The problem of getting clothing to fit well without requiring custom tailoring has been an elusive goal in the garment and clothing pattern industries for many years. Many strategies have been developed for dealing with this problem. Creating and selling loose-fitting styles makes the problem less evident. Many companies take pains to identify the body characteristics of a "target market", a subset of the general population with identifiable body proportions. Many sizing schemes have been developed, particularly for women's clothing, including Misses, Womens, Half-sizes, Juniors, Petites, Junior Misses, etc. The proliferation of sizes makes it uneconomic for a manufacturer to produce and a retailer to stock all styles in all sizes. Extensive statistical studies have been undertaken with the aim of developing sets of standard sizes that will fit the majority of the population.
Typically, a prior art pattern used in the construction of clothing is generated as follows:
1. A skilled designer sketches a new design. After approval these sketches are sent to a pattern making department.
2. A pattern maker drafts a standard size (typically size Misses 10 for women's garments) flat-paper realization of the design using a set of generic parts called slopers as a starting point. This realization is then implemented in muslin and other fabrics and tested on mannequins and models. Once the designer approves the final realization of the design, the pattern pieces are sent to the grading department.
3. A grader generates a set of garment part outlines for each of the standard sizes in which it is desired to produce the design (e.g. Misses 6, 8, 10, 12, 14, 16, 18, 20, 22). This may be done by hand or with the use of a computerized grading system. The hand method involves tracing the original, moving the important points in or out as needed, and then redrawing the lines. If grading is being done with a computerized grading system, the grader assigns grading rules to each important point of each pattern piece, and the computer generates the outlines and draws the results. A grading rule is typically a set of (x, y) offsets, one per size, that specify how a given point is to be moved to represent a particular grade. Steps 2 and 3 are typically repeated for each size range (e.g. Misses, Juniors, Petites, Womens, etc.) because of the difficulty in expressing the more complex changes required to move between ranges with current systems.
4. If the pattern is intended for the home sewing market, the pattern pieces are labeled and laid out for printing on tissues; if the pattern is for a manufacturing operation, a manual or computerized marker-making system lays out the pattern pieces on the fabric, and either the markers are printed, for a manual cutting operation, or the computer drives an automated fabric cutter.
There are a number of inefficiencies with these processes. They affect manufacturers, retailers, and home sewers. These include but are not limited to high labor costs, printing costs, reorder and handling costs, inventory costs, space costs, stock shortages on popular items, and poor fit.
Many tailors and seamstresses spend their time hand-altering commercially manufactured garments. Many people are simply unable to find a ready-to-wear garment that fits in a desired style either because the garment is not manufactured in their size or because the standard sizes produced by a particular manufacturer do not match well with a particular customer's body measurements.
Fit problems for the pattern industry have been addressed by a number of approaches. The pattern houses often include alteration lines for lengthening and shortening sleeves and legs. Even so, home sewer typically modifies a pattern before sewing the garment, and then disassembles, alters, and re-sews the garment repeatedly in an attempt to achieve satisfactory fit. Several companies host traveling seminars designed to teach pattern modification techniques, and there have been previous attempts to produce computer-altered garments and garment patterns (a description of pattern modification techniques is in Jan Minott, Pants and Skirts Fit for Your Shape, Burgess Publishing, Minneapolis, Minn., 1974). None of these approaches adequately addresses the range of alterations necessary on the wide selection of garments and garment patterns that are available today.
Computerized fitting systems have been developed in the past; examples include systems used commercially by Clothing Design Concepts, Box 1188, Manhattan, Kans., and by Richman Brothers Company, Cleveland, Ohio, also described in U.S. Pat. No. 4,598,376. An analytic approach to producing custom-fitted patterns may be found in Francesann Heisey, A Quantitative Methodology for Generating Specifically Fitted Garment Patterns, PhD. Thesis, University of Minn., 1984. These systems have been limited to specific garment patterns, because of the difficulty involved in encoding a garment pattern with detailed fitting information.
Computerized grading systems, which have been in use in the industry for several years, do not have the ability to relate generic garment knowledge to garment pattern data; therefore, a grader is responsible for providing this knowledge through a process of manually assigning grading rules to patterns.
The present invention addresses the major problem that has existed to date in the use of a computerized fitting or grading system, which is the time consuming and error prone process of preparing new patterns as input to the system. This is accomplished by applying knowledge about generic garment types to each new pattern, and by extensive automatic analysis of new patterns based on that knowledge. Once this knowledge has been applied to a new pattern, it may be used to eliminate manual grading operations through a process of the present invention called "knowledge-based grading". The present invention also offers prealteration of garment patterns yielding a high quality fit for a wide range of standard or individual body measurements. As used here, the term "prealteration" refers to automatically applying alterations to a garment pattern, as needed to fit a set of body measurements, before the garment is constructed or the pattern printed. This effectively eliminates the current labor-intensive grading and alteration processes.
The system of the present invention contains knowledge about generic garment styles, including landmarks and other garment features that are expected to be found in garments representative of a garment style and generic constraints that describe detailed relationships between garments and body measurements in terms of the landmarks and other garment features. This knowledge may be applied to raw pattern data by identifying a generic garment style of a garment depicted by the raw pattern data, identifying the expected landmarks and other garment features in the raw pattern data, and then applying the generic constraints to the new pattern. The result is prepared pattern data that includes the knowledge necessary to fit the garment to a set of body measurements. A fitting system is also described that operates by satisfying constraints in a prepared pattern. Such a fitting system need not contain specific knowledge about particular garments.
A prior art system disclosed in U.S. Pat. No. 4,149,246 describes storing information on limitations for a garment (ref. column 7, line 39-40). These limitations refer only to limited choices such as whether a particular type of pocket is appropriate for a particular body type. It is assumed that these limitations have been entered into the prior art system by a system user, such as a designer, for each particular garment or pattern to be processed by the prior art system. Although in column 2, lines 52-54, there is a reference to using nineteen special body measurements for "highly accurate fitting (optional)", there is no disclosure for accomplishing such fitting in the patent, there being reference only to prior art grading systems, such as U.S. Pat. No. 3,391,392 (see column 5 line 49). Further, there is no disclosure of any type of generic knowledge of garment styles, or of the application of generic knowledge to specific garment patterns, as in the present system.
Another prior art system, described in U.S. Pat. No. 4,598,376, operates by modifying reference or pattern points that are stored in a pattern file (ref. column 7, lines 37-39). However, this system includes no storage of generic knowledge of garment styles. Nor is there any disclosure to teach or suggest a data storage structure for the pattern file or a pattern preparation process for identifying the reference or pattern points stored in the pattern file of the system. In contrast to the present system, in which a fitting system need not contain specific knowledge about particular garments, there is no disclosure in U.S. Pat. No. 4,598,376 to suggest that this is possible.